Resilient device



E. E.'ROSS. RESILIENT DEVICE- APPLICATION FILED MAR. 2111916.

Patented May 17, 1921.

Inventor 6W 6 @vv,

UNITED STATES PATENT OFFICE.

EDWARD E. ROSS, OF WILKINSBURG, PENNSYLVANIA.

' RESILIENT DEVICE.

Specification of Letters Patent.

7 I Patented May 17, 1921.

Application filed March 21, 1916. Serial No. 85,578.

Resilient Devices, of which the following is a specification. v

My invention relates to resilient devices and particularly to resilient devices in which both air and aliq'uid are used for producing the resiliency. f

The object of my invention is to provide a cheap, simple and efiicient form of resilient device for use between moving members, such, for example as a pneumatic spring for use on powerdriven vehicles such as motor cars. Another object of my invention is to provide a resilient device in which-air is compressed in an auxiliary chamber for suppl ing the main cushioning chamber.

y invention consists, generally stated in the novel arrangement, construction and combination of parts as hereinafter more -specifically set forth and described and particularly pointed out in the claims.

To enable others skilled in the art to. .which my invention appertains to construct,

us'e'and install my improved resilient device,

-I will explain'the same more fully referring tothe accompanying drawing, in which Figure 1 is a vertical sectional view of one form of device embodying my invention.

Fig. 2 is another form of device showing my invention. a

Fig. 3 is a modified method of supplying air to the top of the cylinder.

Like symbols of reference herein indicate like'p'arts ineach of the figures of the drawmg. I

As illustrated in Fig. 1 of the drawing I have shown a U tube apparatus in order to illustrate my invention but I do not limit myself to any particular form or: shape as the principle of my invention maybe embodied in many difi'erent designs such, .for

instance as in Fig. 2 where I employ a separate chamber 4.

' 7 Considering Fig. 1 the cylinder l-is provided with a piston 2 which operates therein and such piston is provided with the usual piston rod 3 for operating the same. The cylinder 1 is provided with an annular chamber 4, the purpose of which is hereinafter explained. The cylinder 1 and-chaml ber 4 are closed at their outer ends with a cap 5 while said cylinder is closed at its inner end with'a cap 6 which is provided with a bearing 7 in which the piston rod 3 is adapted to operate. The device isprovided with brackets 8 for mounting .the same in position for operation, but these Wlll vary 1n shape and size depending upon the use for which the device is intended. The inner wall 9 of the U tube forming the cylinder 1 is provided with a series of ports 10 at the lower end of the same, and .such ports decrease in width toward their lower extremities, i. e., the cross-sectional area of each port decreases toward the outer end of the cylinder. The piston 2 is secured to the piston rod 3 in any suitable manner such as by threads 11 and the outer face of said piston is provided with a small boss 12 through rings .15. At a point near the upper end of the well 14 the iston rod 3 has a passageway 15' extendlng through the same and such passa eway is connected by a passa e-' way 16 leading to a check valve 17 while t e spring 18 of such valve rests upon and is supported by the pin 13. A spiral spring 19 lies between the outer face of the piston 2- and .within the recess 5 in the cap 5 to hold the piston in its raised position under steady load conditions.

The annular chamber 4 may be provided with an ordinary admission valve 20 for admitting air into said chamber as required, while the cap 6 may be rovided with a valve 21 for admitting aira ove the piston 2 in the cylinder 1 when said piston is in a lowered position.

The operation of my improved resilient I.

the line of liquid. This air may be supplied in a compressed state by a pump through the the upper end of the annular chamber 4 above the volume of compressed air.

valve 20, or it may be supplied by the piston itself in the following manner. Under load ing the liquidto be displaced from above the piston to a position beneath the same. This causes the air in the chamber 4 to be compressed to a small volume, and a largerquantity of the liquid will enter the chamber 4 through the ports 10 and remain below This will allow the piston a long travel on its upward stroke and the air will thus be compressed in the cylinder 1 above the piston 2. This air when compressed to a suflicient degree to overcome the pressure of the air in the chamber 4 and the tension of the spring 18 of the check valve 17 will open said valve and pass beneath the piston 2. On the succeeding down stroke of said piston this air so entrapped beneath the same will be carried to the ports 10 where it will pass into the chamber 4, adding to the air already contained therein and displacing some of the liquid in said chamber into the cylinder 1. The addition of thisamount of liquid in the cylinder 1 will shorten the upstroke of the piston 2, so that on the succeeding upstroke of the plston a smaller volume of air will be passed from the upper to the lower side of said piston. his air is in like manner. transferred into the chamber 4 and the upstroke of the piston still further shortened. This action continues until sufficient air has been pumped into the chamber 4. The upstroke of the piston will then be so shortened that it will be unable to compress the air above the piston 2 sufficiently to operate the check valve 17. When this condition'is ports 10 into the chamber 4 and further comressing the air entrapped therein. At the ower end of its stroke the piston 2 gradually covers the ports 10 and due to their shape the orifice is caused to decre se thereby increasing the friction of the l iquid in passing from the cylinder 1 to the chamber 4. This has the very desirable effect of in troducing a gradual and positive dam ping' action to the motions of the moving member.

When the forces acting on the moving membsir'are r d ed the p ss reo the air in the The cap 6 may be unscrewed from through the ports 10 into the cylinder "1 and return thepiston to its original position. The tendency of the moving member to travel past its original position is here liquid in passing from the chamber 4to the cylinder 1 through the ports 10 and also, by the compression of the air in the chamber 1 above the piston 2.

In the normal operationof this device, it

:chamber 4 causes the liquid tdfloiw therereduced by the friction encountered by the I is desirable that a small amount of liquid be allowed to escape past the piston 2 into the cylinder 1 above the said piston. To pre vent an accumulation of liquid interfering with theproper motion of the piston 2 the check valve 17 will operate to return the I excess liquid from the chamber above the piston to the space below as previously de-- scribed in the method of charging the de -vice.

When the apparatus has been'allowed to stand quiescent for a long period the leakage of oil to the chamber above the piston may become excessive, and in an application of a the device where it is deemed undesirable to await the return of the liquid in the .'pre-- viously described manner, the napparatus 'may be provided with a mechanical spring whose function is to support the piston under steady load conditions.

In. the operation of charging the device it may be necessary to supply the space above the piston 2 with fresh charges of air and to this end any of the well recognized methods may be employed, as for example the check valve 21 shown in Figs. 1 and 2, or

the slotted piston rod 22 shown in Fig. 3,.

myself to form, as for example, a conical form having a smaller cross-sectional area, at the top would give the effect of a spring of.increasing scale while a conical form having a larger cross-sectional area atthe top would give the efi'ect' of a spring of decreasing scale.

Various modifications and changes in the designs, construction and operation of my improved resilient device may be resorted to without departing from, the spirit of the invention or sacrificing any of its advanta es.

to secure by Letters Patent is z- 1. A resilient device comprising a cylinder, a piston operating therein, a chamber at I claim as my invention and desire containing liquid upon which entrapped air acts, a check valve in' said piston for controlling communication between the upper and low r face of aid piston, nd p rts of communication between said cylinder and tween said cylinder and said chamber so de- 4 signed and located as to control recoil of the device by causing a variation of port opening with variation of piston travel.

3. A resilient device comprising a cylinder, a piston operating therein, a chamber containing liquid upon which entrapped air acts, a spring directlysupporting said piston, and a check valve in said piston for controlling communication between the upper and lower faces of said piston.

4. A resilient device comprising a cylinder, a piston operating therein, a chamber containing liquid upon which entrapped air acts, a s ring directly supporting said pis ton, a'c eck valve in said-piston for controlling communication between the upper and lower-faces of said piston, and ports of communication between said cylinder and said chamber so designed and located as to control recoilof the device by causing a variation of port opening with variation of piston travel.

5. A resilient device comprising a cylinder closed at both ends, a piston operating therein, a chamber containing liquid upon which entrapped air acts, a spring directly supporting said piston, and a check valve in said piston controlling communication between the upper and lower faces of said piston, the operation of said check valve being controlled by the variations in the travel of said piston. x

6. A resilient device comprising a cylinder closed at both ends, a piston operating therein,.a chamber containing liquid upon which entrapped air acts, a spring directly supporting said piston, a checl; valve in said piston controlling communicatlon between the upper and lower 'faces of said piston, the operation of said check valve being controlled bythe variations in the travel of said piston, and ports of communication between said cylinder and said chamber so designed and located as to control recoil of the device by causing a variation of port opening with variation of piston travel.

7. In a resilient device, the combination of a fixed= member, a movable memberfor carrying. the load, a column of liquid, and

a chamber containing entrapped air whose pressure transmitted through said column assists in supporting said load, the channel of said column being automatically restrict ed in the operation of said device in such manner thatsaid column variably retards movement of said member.

8. In a resilient device: the combination of a fixed member, a movable member for carrying the load, a mechanical spring operating between said fixed and movable members and partially supporting the load, a column of liquid, and a chamber containing entrapped air whose pressure transmitted through said column assists in supporting said load, the channel of said column being automatically restricted in the operation of said device in such manner that said column variably retards movement of said member.

In testimony whereas I, the said EDWARD E. Ross, aifix my signature in the presence 

